Breakdown of the blood-brain barrier in neuromyelitis optica: Roles of matrix-metalloproteinases-2/9, vascular endothelial growth factor and autoantibodies against the blood-brain barrier

2014 ◽  
Vol 5 (1) ◽  
pp. 2-3
Author(s):  
Fumitaka Shimizu ◽  
Ayako Tasaki ◽  
Takashi Kanda
Stroke ◽  
2020 ◽  
Vol 51 (9) ◽  
pp. 2844-2853 ◽  
Author(s):  
Su Jing Chan ◽  
Elga Esposito ◽  
Kazuhide Hayakawa ◽  
Emiri Mandaville ◽  
Raymond A.A. Smith ◽  
...  

Background and Purpose: Although VEGF 165 (vascular endothelial growth factor-165) is able to enhance both angiogenesis and neurogenesis, it also increases vascular permeability through the blood-brain barrier. Heparan sulfate (HS) sugars play important roles in regulating VEGF bioactivity in the pericellular compartment. Here we asked whether an affinity-purified VEGF 165 -binding HS (HS7) could augment endogenous VEGF activity during stroke recovery without affecting blood-brain barrier function. Methods: Both rat brain endothelial cell line 4 and primary rat neural progenitor cells were used to evaluate the potential angiogenic and neurogenic effects of HS7 in vitro. For in vivo experiments, male Sprague-Dawley rats were subjected to 100 minutes of transient focal cerebral ischemia, then treated after 4 days with either PBS or HS7. One week later, infarct volume, behavioral sequelae, immunohistochemical markers of angiogenesis and neural stem cell proliferation were assessed. Results: HS7 significantly enhanced VEGF 165 -mediated angiogenesis in rat brain endothelial cell line 4 brain endothelial cells, and increased the proliferation and differentiation of primary neural progenitor cells, both via the VEGFR2 (vascular endothelial growth factor receptor 2) pathway. Intracerebroventricular injection of HS7 improved neurological outcome in ischemic rats without changing infarct volumes. Immunostaining of the compromised cerebrum demonstrated increases in collagen IV/Ki67 and nestin/Ki67 after HS7 exposure, consistent with its ability to promote angiogenesis and neurogenesis, without compromising blood-brain barrier integrity. Conclusions: A VEGF-activating glycosaminoglycan sugar, by itself, is able to enhance endogenous VEGF 165 activity during the post-ischemic recovery phase of stroke.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Monique C. P. Mendonça ◽  
Edilene S. Soares ◽  
Leila M. Stávale ◽  
Evanguedes Kalapothakis ◽  
Maria Alice Cruz-Höfling

Phoneutria nigriventerspider accidental envenomation provokes neurotoxic manifestations, which when critical, results in epileptic-like episodes. In rats,P. nigriventervenom (PNV) causes blood-brain barrier breakdown (BBBb). The PNV-induced excitotoxicity results from disturbances on Na+, K+and Ca2+channels and glutamate handling. The vascular endothelial growth factor (VEGF), beyond its angiogenic effect, also, interferes on synaptic physiology by affecting the same ion channels and protects neurons from excitotoxicity. However, it is unknown whether VEGF expression is altered following PNV envenomation. We found that adult and neonates rats injected with PNV showed immediate neurotoxic manifestations which paralleled with endothelial occludin,β-catenin, and laminin downregulation indicative of BBBb. In neonate rats, VEGF, VEGF mRNA, and Flt-1 receptors, glutamate decarboxylase, and calbindin-D28k increased in Purkinje neurons, while, in adult rats, the BBBb paralleled with VEGF mRNA, Flk-1, and calbindin-D28k increases and Flt-1 decreases. Statistically, the variable age had a role in such differences, which might be due to age-related unequal maturation of blood-brain barrier (BBB) and thus differential cross-signaling among components of the glial neurovascular unit. The concurrent increases in the VEGF/Flt-1/Flk-1 system in the cerebellar neuron cells and the BBBb following PNV exposure might imply a cytokine modulation of neuronal excitability consequent to homeostatic perturbations induced by ion channels-acting PNV neuropeptides. Whether such modulation represents neuroprotection needs further investigation.


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